US2298113A - Lightweight electric iron - Google Patents

Description

Oct 6, 19 2. v J K ELY 2,29s,113

LIGHTWE IGI IT ELECTRIC IRON 7 Filed Dec. 7, 1940 WITNESSES: INVENTOR A'iTORNEY iii;

4%; V (ii/ahas/CE/y. l

' peratures of about 250$ C. to 325 C.

Patented Oct. 6, 1942 7 LIGHTWEIGHT ELECTRIC IRON James K. Ely, Wilklnsburg, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsyl- Vania Application December 7, 1940, Serial No. 369,020

a 3 Claims. (Cl. ss 93 This invention relates to pressing or sad-irons and, more particularly, to lightweight irons.

Since a pressing or sad-iron must be moved by the hand of an operator, usually a housewife or maid, there has been a universal demand for a really lightweight sad-iron. Various ingenious attempts have been made and are being made to reduce the weight of the present well-known irons. Most of these attempts have failed to produce the desired light-weight iron because the sole plate employed was formed from cast iron.

In other irons, aluminum has-been employed as the sole plate or ironing surface, but these irons provide a lightweight aluminum base iron having an inexpensive, easily applied, hard backing layer for the metallic iron surface, the backing layer functioning to tenaciousiy bond the metallic ironing surface to the aluminum base, thereby providing a permanent hard glossy exposed ironing surface irrespective of the operating temperature I of the iron.

have not proven to be satisfactory commercially as they are easily dented and marred. Where precipitation hardened aluminum alloy sole plates are employed, it is found that they cannot retain their hardness at the high operating temand are, therefore, easily marred and the flat ironing surface destroyed in a very short time under the blows and other conditions encountered in normal service.

' Other irons have been produced having an aluminum sole plate to which a chromium coating has been electrolytically applied. Heretofore, the aluminum irons having a chromiumironing surface have failed in a relatively short'p'eriod of time because the chromium surface did not permanently adhere to the aluminum sole plate. Instead, it is found that slight blows, suchas are encountered in service, destroy the bond between the sole plate and thechromium plating with the result that the chromium plate blistered and peeled unevenly over the surface of the sole plate. It is thought that one of the reasons for the failure of these aluminum irons was that the aluminum metal utilized as the sole platelis so soft or where a precipitation hardened aluminum alloy is employed, becomes so soft under the operating temperatures encountered, as-to fail to provide a sufiiciently hard backing for the chromium plate.

It is, therefore, desired to produce a lightweight jron, preferably of aluminum or aluminum base alloys, which will withstand the usual rough treatment given an iron and which has an ironing surface formed of anexterior metallic plating so bonded thereto as to a sufliciently hardbacking for the metallic platprevent blistering or peeling thereof while at the same time providing Another object of this invention is to provide a lightweight iron of aluminum or aluminum base alloy having a chromium ironing surface bonded thereto by means of a hard backing layer composed of an oxide.

Another object of this invention is to provide a lightweight iron of aluminum or aluminum base alloy having a chromium ironing surface bonded thereto by means of intermediate layers composed of a hard backing layer of an oxide and a-layer of nickel electrolytically deposited thereon.

Other objects of this invention will become apparent from the following description when talten in conjunction with the accompanying drawing,

in which: Figure 1 is a perspective view of an iron embodying this invention;

Fig. 2 is a transverse sectional view of the iron shown in Fig. 1; i

Fig. 3 is a fragmentary sectional view' taken along the line III--III of Fig; 2; and

- Fig. 4 is a view similar to Fig. 3 illustrating another embodiment of this invention.

Referring to the drawing, in which like reference characters indicate like parts .in the sev-' eral figures, an iron structure I0 is fllustrated comprising a lightweight aluminum orfaluminum ,alloy base or sole plate I? and an electric heat-- ing element l4 disposed therein for heating the sole plate. The heating element l4, while being shown as cast, or embedded within the sole plate l2 may, however, be associated with the base l2 in any other desired manner. The operation of the electric heating element 14 is selectively controlled by a thermostattlfi in a well known man- 7 In accordance withthis invention, thealumiing that the iron will maintain these desirable characteristics during operation over a wide range of temperatures.

with an exterior hard lustrous coating forming the ironing surface, as will be explained more fully hereinafter, Since the aluminum sole plate l2 is inherently relatively soft and easily dented, the iron surface is formed of a plurality of layers of suitable material for increasing the scratch and dent resistance of the sole plate during normal usage of the iron.

Referring to Fig. 3 of the drawing, there is illustrated a preferred embodiment of this invention in which a hard backing layer It is applied to the aluminum or aluminum alloy base i2, afterwhich a layer of chromium 20 is applied to the backing layer [8 for providing the desired hard and lustrous ironing surface.

, on the sole plate. This can readily be appre- .The layer It is preferably formed of aluminum oxide deposited in any desired manner such as, for example, by anodizing the sole plate in oxalic acid for a given period of time. The method of forming the anodized aluminum layer it need not be described in detail however, since different methods are well known in the art and by themselves form no part of the present invention. The layer it formed by any of the well known commercial anodizing methods is quite-hard and is so bonded thereto as to be an integral part of the aluminum sole plate I! 'so that there is no ciated when it is considered thatv aluminum has a thermal conductivity of approximately 33% or about four times that of the cast iron bases employed heretofore. In addition to having a good thermal conductivity. the resulting iron is extremely lightweight by reason of the metals employed in its construction. Further, because of the backing layer of anodized metal, the resulting iron has an ironing surface which is resistant to denting and scratching during normal usage of the iron, while at the same time retaining its desired characteristics throughout operating temdanger of breaking the bond between the layer l8 and the sole plate 12. In addition to being quite hard,. it is found that the anodized layer It provides an ideal medium for electroplating the exterior metallic coating 2|! of chromium thereto.

The metallic layer of chromium is applied to the layer It of anodized aluminum by any suitable method of electroplating, it'being found upon a close examination of the resulting plate thatthe chromium plated on the layer ll actually penetrates the minute interstices formed between the various flakes of oxide giving a definite bond with the layer It. I'he thickness of the exterior chromium coating 20 may be of any magnitude desired, it being understood that the greater the thickness of the chromium plate the greater the resisting power of the composite layers forming the ironing surface to denting.

In practice, after the chromium plate has been peratures of up to as high as about 325 0.

Throughout the description given .hereinbefore aluminum and aluminum base alloys'are considered as. equivalents and where the term aluminum is employed in the appended claims it is intended to include bothaluminum and aluminum base alloys.

Although this invention has been described with reference to a particular embodiment thereof, it will be obvious to those skilled in the art that it is not to be so limited but is susceptible of various changes and modifications without departing from the spirit thereof and that it is, therefore, not to be limited except insofar as such limitation shall be placed thereon as are specifically set forth in the appended claims.

formed and securely bonded to the intermediate anodized layer, the exterior surface is buffed to a high lustrous condition in any of the well known manners to provide an attractive serviceable iron. The combination of the backing layer IQ of the anodized aluminum and the exterior coating of chromium cooperate to provide a very hard, dent and scratch resisting ironing surface on the aluminum sole plate, while at the same time permanently adhering to the sole plate.

In another embodiment of this invention as illustrated in Fig. 4, an intermediate layer 22, preferably nickel, is electrolytically deposited between the layers It and 20 .of anodized aluminum and chromium, respectively, for providing a thicker scratch resisting ironing surface on the sole plate. i2. The thickness of. the layer 22 of nickel in this embodiment may vary, it being found that the I I claim as my invention:

1. An iron comprising an aluminum base having. a working surface,.means to heat said base member operatively associated therewith, a layer of adherent anodized aluminum integrally formed on at least the working surface of the base of the iron, and an exterior metallic coating electroplated upon the layer of anodized aluminum on at least the working surface, the electroplated-coating being integrally bonded throughout the electroplated area with the layer of anodized aluminum, the layer of anodized aluminum cooperating with the exterior metallic coat-v ing to strengthen the exterior coating and render it resistant to physical shock, the bond between i the layer of anodized aluminum, the aluminum base and the exterior metallic coating being so adherent and so resistant to thermal shock that it is capable of withstanding repeated heating to high temperatures without, detrimental effect thereon.

2. An iron comprising an aluminum base having a working surface, means to heat said base thicker the nickel layer, the more resistant the the adjacent layer to the sole plate I2.

member operatively associated'therewith, a layer of adherent anodized aluminum integrally formed on at least the working surface of the base of the iron, and an exterior layer of chromium electroplated upon the layer of anodized aluminum on at least the working surface, the

layer of chromium being integrally bonded throughout the electroplated area with the layer of anodized aluminum, the layer of anodized aluminum cooperating with the layer of chromium to strengthen the exterior layer and render it resistant to physical shock, the bond between the anodized aluminum and each of the base and layer of chromium .beinl so a'dherent and so resistant to thermal shock that it is capable of withstanding repeated heating to tem- Since the iron of this invention utilizes a sole plate of {aluminum or aluminum alloy, it is quite apparent that the iron will function efliciently to transmit the heat from the heating element peratures of up to about 325 0.. without detrimental eifect' thereon.

3. A lightweight hand iron comprising, in combination, an aluminum base member having a to the ironing surface of metallic plating formed '75 lower surface, means to heat said base member operativelyassociated' therewith, "a layer of anodized aluminum integrally and adherently the electroplated layers being integrally bonded to each other and to the anodizedaluminum throughout the entire electroplated areas, the

layer of nickel and the layer of anodized alumi- 10 num cooperating to provide a hard dent resisting medium to strengthen the layer of chromium and render it resistant to shock, the bond be-' tween the different layers and the lower surface being so secure and resistant to thermal shock as to withstand repeated heating to temperatures of up to about 325 C. without detrimental effect thereon.

' JAMES K. ELY.

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